NFC is a short range wireless connectivity technology that enables the exchange of various types of information, such as numbers pictures, MP3 files or digital authorizations between two NFC enabled devices such as mobile phones or between a mobile phone and a compatible chip card or reader that are positioned close to each other. Applications for NFC include use as an access control for content and for services such as cashless payment, ticketing, etc.
NFC is often defined as operating in a frequency range centered on 13.56 MHz. Communications between NFC-capable devices may exist in a variety of modes, including: peer-to-peer; active-passive (or reader-writer); and so-called card emulation.
As NFC technology evolves, it is often desired that a single equipment, illustratively a mobile phone, be capable of acting in more than one mode. For example, a cell phone might be capable of acting (i) in the card emulation mode, thereby facilitating a credit-card purchase transaction; and (ii) in the reader mode, thereby facilitating reading of smart posters or other various tags or other similar devices. In addition, it may be desired for the mobile phone to be capable of peer to peer information exchange with another mobile phone.
These and other modes of operation may have somewhat different power requirements. Those concerned with the development of NFC technology have sought improved architectures, systems, and integrated circuits to facilitate improved performance and versatility of NFC equipments.